Rail-circuit-closing contact.



P. PROCHASKA.

RAIL CIRCUIT CLOSING CONTACT.

APPLICATION FILED JUNE 17, 1909.

WMM- Wd- J@ ma Patented Sept. 2, 1913.

UNITED STATES PATENT OFFICE.

FRIEDRICH PROCHASKA, 0F CHARLOTTENBURG, GERMANY, ASSIGNOR TOSIEMENS &HALSKE A. G., OF BERLIN, GERMANY, A CORPORATION 0F GERMANY.

yRAIL-CIIt()UI'I-CIZIOSING CONTACT.

Specification of Letters Patent.

Patented Sept. 2, 1913.

T o all 'wlmi/1, 'if may concern Be itknown that I, FRIEDRICHPnooiIAsKA, a subject of the Emperor of Austria- Hungary, and residingat Charlottenburg, near Berlin, Germany, have invented certain new anduseful Improvement-s in Rail- Circuit-Closing Contacts, of which thefoilowing is a specification.

My invention relates to rail circuit-closing contacts of the well-knownmercury type,

in which the downward deflection of the rail by the weight of thepassing train is ut-ilized for producing an electric Contact by ressingmercury from a pressure vessel into an adjoining contact vessel in whichan electric contact takes place.

Ill-the art the arrangement is generally such that the pressure vesselis closed at the top by a steel diaphragm, upon which the pressure,exerted by the downward deflection of the rail, is transmitted. Thisarrangement has the disadvantage that owing to the reaction produced bythe inertia of the mercury the diaphragm sufi'ers what might be termedhereinafter a counter de- Hection which tends to distort the diaphragmoppositely to the direction in which the rail tends to distort ordeflect it, and owing to this counter defiection a considerable amountof the motion produced by the defiection of the rail and intended to betransmitted to the mercury is neutralized and thus unavailable, and as aresult too little mercury is pressed into the contact vessel.

`In order to render the reaction of the mercury ineffective the pressurevessel, according to the present' invention, is not covered with adiaphragm but with a strong heavy metal plate, the thickness of which ischosen so that the plate will bend only under the weight. of the loadwhich the car wheel carries and that the reacting pressure caused by theinertia of the mercury is unable to produce an undesirable counterdeflection of the plate.

In order to clearly explain my'invention I have illustrated same in the-accompanying drawings in several modifications.

In these drawings: Figure 1 shows alform of my improved rail contact intransverse sectional elevation. Fig. 2 is a side elevation 'ther-eef.Fig. 3 is a side elevation of a rail portion with the rail contactinterposed directly between the rail and the sleeper. Fig. 4 is atransverse sectionall elevation of a modification of the form shown vinFig. 1, in which the girder which supports the rail contact forms a partof the pressure chamber. Fig. 5 is a transverse sectional elevation ofanother modification in which intermediate members are placed betweenthe rail and the contact device to transmit the pressure from the railto the latter, and Figs. 6 and@ are diagrams showing a difference ineiect on the elastic line of a plate when a comparatively largeintermediate member exerts a pressure upon the walls of a chamber andwhen a comparatively small interkmediate member bears centrally againstthe walls of a pressure chamber.

Referring to Figs. 1 and 2, the contact device consists of two thickiron or steel plates 5 and 7 recessed at the surfaces facing each otherso that a chamber 8 is formed between these plates when they are placedon top of each other. These plates are placed between the underside ofthe rail l and girder 2 which lat-ter is held tight to the rail by meansof clamps 3 which can be tightened by means of screws. 4. The upperplate 5 has laterally of the rail near its rim a thickened portion 9which is provided with a short duct 10 terminating with its lower end inchamber 8 and with its upper end in the Contact vessel 11.. Chamber 8 iscompletely filled with mercury and the duct to a suitable height asshown. The train in passing over rail 1 depresses this rail so thatplates 5 and 7 are deflected toward each other which diminishes thevolume of chamber 8 so vthat the mercury in duct 10rises and contact ismade in contact vessel 11 with cont-act pin 12, by having the mercurysquirted against this pin. The mercury thus ejected from the duct 10returns to chamber 8 by lway of compartment 13. Contact de- 4 vices ofthis character are known in the art and the above construct-ion is onlyshown as an example and may be substituted by any known similar device.The two plates 5 and 7 may be fastened together at their rims in anysuitable manner as for instance by 'welding orbolting (not shown here).Moreover any suitably shaped iron bar or rail ma be used for supportingthe two plates which contain the pressure chamber 8'but I prefer a railhaving a profile similar to that of a railroad rail, such as is shown at2 in Fig. 1. The arrangement of the device is clearly shown in side viewin Fig. 2.

Inasmuch as a pressure vessel constructed in the manner just describedis capable of sustaining a great pressure the supporting gir-der 2 maybe omitted and a pressure vessel 5, 7 of the kind shown in Figs. 1 and v2 may be placed directly between the railmercury in chamber 8.

way rail and the' sleeper 6 as shown in Fig. 3. The top surface ofsupporting girder 2 may be utilized as a wall for the pressure chamber 8on which then plate 5 rests as a top plate with otherwise a similarconstruction as that shown in Fig. 1. This modification is representedin Fig. 4.

The amount of mercury expelled from chamber 8 by the pressure of apassing train may be considerably increased by intei-posing between therail and the upper plate 5 of the pressure vessel an intermediate memberwhich I shall call hereinafter the presser, and the pressure vessel maybe supported at its under side again by a rail 2, which, however, isshaped at its upper side where it contacts with the pressure vesselsimilarly to presser 17.' This modification is illustrated in Fig. 5where the presser' is shown at 17 and the supporting rail at 2a. It willbe noted from this figure that presser 17 and rail 2 are provided Withrims a, with which alone they bear against their respective plates 5 and7 so that they do not abut against the centers of the pressure plates 5and 7. Moreover the presser 17 preferably does not abut against the rail1 with a large surface but a hemispherical equalizing member 18 isinterposed be-v tween the foot of the rail and the presser so that incase the device should not be properly alined the pressure of the railis,

not exerted one sidedly against the presser 17. If this were the casethe heavy vpressure exerted by the t-rain might be transmitted from therail 1 to presser 17 at one side only and at a few points at that, whichmight cause the rail flange or the presser to yield or become indentedunder the`extremely high specific pressure which in turn would lessenthe pressure transmitted to the With the hemispherical -member 18interposed the pressure will always be symmetrically distributed overpresser 17 and in turn be symmetrically transmitted to plate 5. Thisarrangement works to a particular advantage.

The reason why with a presser, alarger amount of mercury may be expelledfrom chamber 8 may be clearly seen from the diagrams shown in Figs. 6and 7. In Fig. 6 the dotted lines which represent the exaggerateddefiection of plates 5 and 7 are produced when 4a-'construction isemployed such as shown in Fig. 5 in which the rail pressure istransmitted through a presser 17 whereas the elastic lines of plates 5and 7, shown in Fig. 7, are produced when the pressure of the rail isimparted directly from the rail cent-rally to the pressure plates 5 and7 or also by a small intermediate member 19. The amount of raildeflection f1 is equal in both instances. In the arrangement shown inFig. 7 the maximum amount which both plates 5 and 7 deflect is also onlyequal to f1. On the other hand in the arrangement shown in Fig. 6 whichdiagrammatically represents Fig. 5, the two plates 5 and 7 are deflectedtoward each .otherI the amount f1 at the rim a of presser 17 and at thecorresponding rim of supporting rail 2, whereas both plates are morestrongly deflected at their centers, the deflection being there equal tof2. Thus 1t will be clearly seen that under otherwise equal conditionsthe volume of the chamber is decreased a greater amount by using thearrangement diagrammatically represented in Fig. 6 than in case of thearrangement illustrated in Fig. 7.

What I claim is:

`1. In a railway contact device, the combination etav pressure vesseladapted to contain mercury and disposed underneath the rail and suitablysupported to remain in contact therewith, said vessel having a heavy topplate flexible only under the weight of a train and adapted to therebyexert a pres- Sure on the mercury without eounter-deflec-- tion due tothe mercury, and a contact vessel containing electric contact terminalsadapted to be connected by the mercury, said vessel being disposedadjacent to and connected with said pressure vessel to permit themercury expelled from the pressure vessel to rise in said contact vesselto make the desired contact.

2. In a railway contact device, the combination of a pressure vesseladapted to contain mercury and disposed underneath the rail and suitablysupported to remain in contact therewith, said vessel having -a heavyrecessed metal top plate flexible only underV the weight of a train andadapted to thereby exert a pressure on the mercury withoutcounter-deflection due to the mercury, and a contact vessel containingelectric contact terminals adapted to be connected by the mercury, saidvessel being disposed adjacent to and connected with said pressurevessel to permit the mercury expelled from the pressure vessel to frisein said contact vessel to make the desired contact.

3. In a railway contact device, the combination of a pressure vesseladapted to contain mercury and disposed underneath the rail and suitablysupported to remain in contact therewith, said vessel comprising twoheavy recessed plates fitting tightly together at their rims, andfiexible only under the Weight of a train and adapted to thereby exert apressure on the mercury without counter-deflection due to the mercury,and a contactvvessel containing electric contact terminals adapted to beconnected bythe mercury, said vessel being disposed adjacent to andconnected with said pressure vessel to permit the mercury expelled fromthe pressure vessel to rise in said contact vessel to make the desiredcontact.

4. In a railway contact device, thecombination of a pressure vesseldisposed underneath the rail, adapted 'to contain mercury and having aheavy top plate responsive to deflection by the rail only under thetrain weight, a contact vessel disposed in close proximity to saidpressure vessel containing electric contact terminals adapted to beconnected by the mercury, said vessel having a short communication withsaid pressure vessel to permit the mercury expelled from the pressurevessel to rise in said contact vessel FRiEDRIcH PRocHAsKA.

Witnesses WOLDEMAR HAUPT, HENRY HASPER.

